TY - JOUR
T1 - Life history and chemical defense interact to drive patterns of adaptation in an annual monkeyflower
AU - Scharnagl, Anna
AU - Genung, Mark A.
AU - Holeski, Liza M.
AU - Kooyers, Nicholas J.
N1 - Publisher Copyright:
© The Author(s) 2022. Published by Oxford University Press on behalf of The Society for the Study of Evolution (SSE). All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
PY - 2023/2/4
Y1 - 2023/2/4
N2 - Although chemical defenses and herbivore pressure are widely established as key targets and agents of selection, their roles in local adaptation and determining potential evolutionary responses to changing climates are often neglected. Here, we explore fitness differences between 11 rangewide M. guttatus populations in a field common garden experiment and assess the agents and targets of selection driving relative fitness patterns. We use piecewise structural equation models to disentangle associations between chemical defenses, (phenylpropanoid glycosides; PPGs), and life history traits with herbivory and fitness. While the historical environment of populations is not predictive of fitness differences between populations, >90% of variation in fitness can be predicted by the flowering time and foliar PPG defense arsenal of a population. Piecewise structural equation models indicate that life history traits, particularly earlier flowering time, are strongly and directly linked to fitness. However, herbivory, particularly fruit predation, is also an important agent of selection that creates indirect links between fitness and both chemical defenses and life history traits. Our results emphasize the multivariate nature of the agents and targets of selections in producing adaptation and suggest that future responses to selection must navigate a complex fitness landscape.
AB - Although chemical defenses and herbivore pressure are widely established as key targets and agents of selection, their roles in local adaptation and determining potential evolutionary responses to changing climates are often neglected. Here, we explore fitness differences between 11 rangewide M. guttatus populations in a field common garden experiment and assess the agents and targets of selection driving relative fitness patterns. We use piecewise structural equation models to disentangle associations between chemical defenses, (phenylpropanoid glycosides; PPGs), and life history traits with herbivory and fitness. While the historical environment of populations is not predictive of fitness differences between populations, >90% of variation in fitness can be predicted by the flowering time and foliar PPG defense arsenal of a population. Piecewise structural equation models indicate that life history traits, particularly earlier flowering time, are strongly and directly linked to fitness. However, herbivory, particularly fruit predation, is also an important agent of selection that creates indirect links between fitness and both chemical defenses and life history traits. Our results emphasize the multivariate nature of the agents and targets of selections in producing adaptation and suggest that future responses to selection must navigate a complex fitness landscape.
KW - Erythranthe guttata
KW - Mimulus guttatus (common monkeyflower)
KW - common garden
KW - flowering time
KW - frugivory
KW - herbivory
KW - piecewise structural equation modeling
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U2 - 10.1093/evolut/qpac048
DO - 10.1093/evolut/qpac048
M3 - Article
C2 - 36611283
AN - SCOPUS:85147458174
SN - 0014-3820
VL - 77
SP - 370
EP - 383
JO - Evolution; international journal of organic evolution
JF - Evolution; international journal of organic evolution
IS - 2
ER -